Data storage system

ABSTRACT

In a file system in which data is distributively stored on a plurality of volumes in compliance with file storage requests from business applications, the present invention calculates reliability requirements or performance requirements which represent storage requirements for the storage of individual files requested for storage, selects an actual file storage destination volume in accordance with the reliability characteristics or performance characteristics of each volume, and storage file data on the selected storage destination volume. Since the storage requirements are calculated to select a storage destination volume for each file, data storage destination optimization can be achieved on an individual file basis.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a data storage system, and moreparticularly to file storage destination volume selection control thatis exercised when files used by a number of business applications are tobe stored on volumes in a NAS (Network Attached Storage) system or otherfile system for distributively storing data on a plurality of volumes.

[0003] 2. Description of Related Art

[0004] It is demanded that storage volumes offer an increased storagecapacity in order to handle an increasing amount of data. Further, theimportant factors for storage devices are reliability characteristicsand performance characteristics. The reliability characteristics aredetermined according, for instance, to the frequency of device failureand the capability for protecting stored data from damage in the eventof a failure. The performance characteristics affect the read/writespeed for the stored data or the data to be stored. It can be said thatthese characteristics determine the properties of storage volumes.

[0005] Meanwhile, the data to be stored on storage volumes occasionallyvary in properties. It is therefore important that a storage volumehaving optimum reliability characteristics and performancecharacteristics be selected in accordance with the requirements for thedata to be stored. For example, customer data and other mission-criticaldata should be stored on a highly fault-tolerant volume such as a RAID5or RAID1 type. Video data, on the other hand, should be stored on ahigh-speed sequential access volume for effectiveness enhancementpurposes.

[0006] In the following description, the expression “data storagedestination optimization” is used to indicate the act of storing data ona storage volume having optimum reliability characteristics andperformance characteristics in accordance with the requirements for thedata to be stored.

[0007] Conventional data storage destination optimization was basicallyachieved by an administrator who manually managed the reliabilitycharacteristics, performance characteristics, and mount point directoryof each volume.

[0008] Some large-size disk devices and virtualization productsdeveloped in recent years have a data migration function. This functionworks so that data previously allocated to a certain volume can be latermoved to another volume, which differs in reliability characteristicsand performance characteristics from the first one. Typical examples ofthis functionality are the data migration function of a storagesubsystem product manufactured by Hitachi, Ltd. and the data migrationfunction of a virtualization product manufactured by Data Core SoftwareCorporation in the U.S.

SUMMARY OF THE INVENTION

[0009] However, there are the following problems with the aforementionedconventional methods.

[0010] The first problem is that data storage destination optimizationcannot be achieved on an individual file basis although it can beaccomplished on an individual volume basis. More specifically, the dataarrangement cannot be optimized for each file because all the filesunder the same mount point will be stored on the same volume. Therefore,even if a frequently random accessed file and a frequently sequentialaccessed file exist in the same directory, they cannot be stored onrespective volumes that differ in reliability characteristics andperformance characteristics.

[0011] The second problem is that a business application manager must beaware of the characteristics and mount point of each volume. As aresult, data storage destination optimization cannot be achieved withoutbeing aware of the reliability characteristics, performancecharacteristics, and mount point destination of each physical volume.If, for instance, an index file is to be stored on a high-speed randomaccess storage, a complicated procedure needs to be performed during theuse of a conventional technology. More specifically, the use of aconventional technology makes it necessary to locate a high-speed randomaccess volume, mount it in an appropriate directory, and perform setupso that the index file will be stored in that directory.

[0012] It is an object of the present invention to provide a datastorage system that achieves data storage destination optimization on anindividual file basis.

[0013] It is a further object of this invention to automaticallycalculate storage requirements and determine the storage destinationvolume for data storage destination optimization on an individual filebasis, thereby saving a system administrator the trouble of setting aspecific volume and its mount destination.

[0014] To achieve the above objects, the present invention automaticallycalculates storage requirements and determines the storage destinationvolume on an individual file basis. Preferably, the present inventioncalculates the reliability requirements or performance requirements,which are the storage requirements for file storage, in relation to eachfile specified by a storage request, selects a storage destinationvolume in accordance with the calculated storage requirements and thereliability characteristics or performance characteristics of eachvolume, and stores a file on the selected storage destination volume.Typical information representing the reliability requirements is themean time between failure and average operating time. Typicalinformation representing the performance requirements is an accessspeed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a schematic diagram that shows the configuration of aNAS system of a preferred embodiment according to the present invention;

[0016]FIG. 2 illustrates the operation of a storage destinationselection engine 101 shown in FIG. 1;

[0017]FIG. 3 outlines the flow of a process that is performed by thestorage destination selection engine 101 shown in FIG. 1;

[0018]FIG. 4 illustrates the contents of a storage requirementcalculation rule indicated in FIG. 1;

[0019]FIG. 5 illustrates the contents of a storage destination volumecalculation rule;

[0020]FIG. 6 is a flowchart illustrating the processing steps forstorage requirement calculation;

[0021]FIG. 7 is a flowchart illustrating the processing steps forstorage destination volume calculation;

[0022]FIG. 8 is a flowchart illustrating the processing steps that areperformed by a storage requirement calculation rule setup engine 102;and

[0023]FIG. 9 is a flowchart illustrating the processing steps that areperformed by a storage destination volume calculation rule setup engine103.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A preferred embodiment of the present invention will now bedescribed with reference to a NAS system, which is cited as an exampleof a file system for distributively storing data on a plurality ofvolumes.

[0025] The NAS system cited as an example for the description of theembodiment is simpler than a common NAS system because the former iswithout irrelevant functions and other details unnecessary for thedescription of the present invention. However, this description is notnecessarily intended to limit the scope of the invention.

[0026]FIG. 1 is a schematic diagram that shows the configuration of aNAS system of a preferred embodiment.

[0027] This NAS system includes a NAS server 110, NAS clients 130, and aLAN 120 for connecting the NAS server to the NAS clients.

[0028] Within the NAS clients 130 of the preferred embodiment, businessapplications 131 are executed. The business applications 131 send a filestorage request to the NAS server 110 via the LAN 120. The NAS server110 comprises a main storage device 161, a communication device 162, aCPU 163, a display device 164, a keyboard 165, a mouse 166, and asecondary storage device section 167.

[0029] The secondary storage device section 167 comprises two types ofvolume devices: a plurality of storage destination volumes 171 forstoring data for which a storage request may be issued from the NASclients 130 and a management information storage volume 172 forretaining the NAS server's management information. The managementinformation storage volume 172 stores a storage requirement calculationrule 181 and a storage destination volume calculation rule 182. The mainstorage device in the NAS server stores an operating system 140.

[0030] Within the operating system 140, a storage destination selectionengine 101 for selecting a storage destination volume for each file, astorage requirement calculation rule setup engine 102 for setting thestorage destination requirement calculation rule 181, and a storagedestination volume calculation rule setup engine 103 for setting thestorage destination volume calculation rule 182 are executed incompliance with storage requests from the business applications 131 onthe NAS clients 130.

[0031] The above three engines are stored as program data in thesecondary storage device section 167. At system startup, these enginesare loaded from the secondary storage device section 167 into the mainstorage device 161 and executed by the CPU 163.

[0032] Although a NAS system for generating file storage requests via anetwork is described in the preferred embodiment, the present inventionis also applicable to a common file system in which the businessapplications 131 and the storage destination volumes 171 are installedon the same computer.

[0033]FIG. 2 illustrates the operation of the storage destinationselection engine 101 of the embodiment. FIG. 3 outlines the flow of aprocess that is performed by the storage destination selection engine101 of the embodiment.

[0034] The operation and process performed by the storage destinationselection engine 101 will be outlined below with reference to FIGS. 2and 3.

[0035] Upon a storage request from a business application 131, a filereception module 200 receives a file requested for storage 201 (filereception step 301).

[0036] Next, a storage requirement calculation module 210 references thestorage requirement calculation rule 181 and calculates the reliabilityrequirements and performance requirements for the file as storagerequirement information 241 (storage requirement calculation step 302).

[0037] Next, a storage destination volume calculation module 220references the storage requirement information 241 and storagedestination volume calculation rule 182 and calculates storagedestination volume information 242, which designates a specific storagedestination volume (storage destination volume calculation step 303).

[0038] Finally, a storage module 230 stores the file requested forstorage 201 on a storage destination volume 171 that is specified by thestorage destination volume information 242, which was determined in thepreceding step (storage step 304).

[0039] The storage requirement calculation step 302 and storagedestination volume calculation step 303, which are among the aboveprocessing steps, will now be described in detail.

[0040] For the purpose of describing in detail the storage requirementcalculation step 302 and storage destination volume calculation step303, the contents of the storage requirement calculation rule 181 andstorage destination volume calculation rule 182 will be described inadvance.

[0041]FIG. 4 illustrates the contents of the storage requirementcalculation rule 181.

[0042] The storage requirement calculation rule 181 retains a businessapplication versus storage requirement mapping table 410.

[0043] The business application versus storage requirement mapping table410 calculates the storage requirements for a specific businessapplication related to a storage request, that is, the reliabilityrequirements and performance requirements for a file requested forstorage. The use of this table makes it possible to calculate thestorage requirements appropriate for the business applicationcharacteristics. If, for instance, a database application issues arequest for storing a file, this table can conclude that the file needsto be stored on a volume that meets high reliability requirements andhigh performance requirements.

[0044] The business application versus storage requirement mapping table410 retains reliability requirements 412 and performance requirements413 for each business application type 411. It is preferred that themean time between failure, average operating time, RAID configuration(e.g., the RAID1 reliability is higher than that of RAID5), and otherparameters be used as the reliability requirements, and that the accessspeed and other parameters be used as the performance requirements.

[0045] The embodiment uses a structure so that the reliabilityrequirements and performance requirements are calculated for eachbusiness application type. However, if the contents of column 411 arechanged, for instance, to represent an operating system user type or NASclient type instead of a business application type, the storagerequirement calculations can be based on a factor other than a businessapplication type.

[0046] In the embodiment, the storage requirement calculation rule ispredefined. However, the reliability requirements, performancerequirements, and other storage requirements may be alternatively setfor individual business applications targeted for storage so as to usethe storage requirements set for business applications when a storagerequest is received from business applications.

[0047] Although the embodiment assumes only two definable values (“high”and “low”) for the reliability requirements 412 and performancerequirements 413, various other values, including real values, may bealternatively used in reality instead of the two values (“high” and“low”).

[0048]FIG. 5 illustrates the contents of the storage destination volumecalculation rule 182.

[0049] The storage destination volume calculation rule 182 includes astorage destination volume versus characteristics mapping table 510, astorage destination volume usage priority definition table 520, and avolume type versus characteristics mapping table 530.

[0050] The storage destination volume versus characteristics mappingtable 510 retains the reliability requirements 511 and performancerequirements 512 for each storage destination volume 513. When thereliability requirements and performance requirements for a file areused as the key to search this table, a specific storage destinationvolume can be calculated.

[0051] The storage destination volume usage priority definition table520 is used as an auxiliary for storage destination volume selection. Iftwo or more storage destination volumes are designated as candidateswhen the file reliability requirements and performance requirements arecompared against the storage destination volume versus characteristicsmapping table 510, one storage destination volume is selected accordingto the usage priority defined in the storage destination volume usagepriority definition table. This table 520 retains the information aboutthe usage priority level 522 of each storage destination volume 521.

[0052] The volume type versus characteristics mapping table 530 is usedwhen the storage destination volume calculation rule setup engine 103deductively generates the data for the storage destination volume versuscharacteristics mapping table 510 and storage destination volume usagepriority definition table 520 in accordance with the storage destinationvolume manufacturer and type. The volume type versus characteristicsmapping table 530 retains the information about manufacturers 531,volume types 532, reliability characteristics 533, performancecharacteristics 534, and capacity unit price 535.

[0053] Next, the storage requirement calculation step 302 will bedescribed. FIG. 6 is a flowchart that illustrates how the storagerequirement calculation step 302 is performed.

[0054] First, the type of the business application that has issued astorage request is used as the key to search the business applicationversus storage requirement mapping table 410 within the storagerequirement calculation rule 181 (step 601). The type of the businessapplication that has issued a storage request can be acquired in variousways. For example, the type possessed by a business applicationattempting to store data can be set in a storage request instructionparameter to acquire the business application type at the time ofstorage request instruction decoding or can be made known when anattempt is made to log on to the NAS system for sending a storagerequest. If the business application versus storage requirement mappingtable shown in FIG. 4 consists of user names, reliability requirements,and performance requirements, the user name of a user who issues astorage request is used as the key to search the business applicationversus storage requirement mapping table.

[0055] If a matching record is found in the search conducted in step601, the program flow proceeds to step 603; however, if no matchingrecord is found, the program flow proceeds to step 604 (step 602). Inthe former case, the reliability requirements and performancerequirements are acquired from the matching record found in step 601(step 603). In the latter case, on the other hand, the businessapplication that has issued a storage request is not registered;therefore, the business application versus storage requirement mappingtable 410 is searched for the default storage requirements to acquirethe reliability requirements and performance requirements (step 604).

[0056] The reliability requirements and performance requirementsacquired in step 603 or 604 are then passed to the storage destinationvolume calculation step 303 as the storage requirement information 241(step 605). When step 605 is completed, the reliability requirements andperformance requirements retained by the storage requirement information241 become the reliability requirements and performance requirements forthe file requested for storage, which are suitable for the type of thebusiness application that has issued a storage request.

[0057] The storage destination volume calculation step 303 will now bedescribed. FIG. 7 is a flowchart that illustrates how the storagedestination volume calculation step 303 is performed.

[0058] The storage requirement information 241 calculated in the storagerequirement calculation step 302 is referenced to acquire thereliability requirements and performance requirements (step 701). Thereliability requirements and performance requirements acquired in step701 are used as the key to search the storage destination volume versusstorage requirement mapping table 510 under the conditions where the twosets of requirements are ANDed (step 702). If any matching record isfound in the search conducted in step 702, step 710 is performed next;however, if no matching record is found to be in compliance with theconditions where the two sets of requirements are ANDed, step 704 isperformed next (step 703).

[0059] Step 710 is performed so as to handle the search result as astorage destination candidate, and then the program flow proceeds tostep 711. The search result indicates a storage destination volumeappropriate for storing the target file, that is, the storagedestination volume that satisfies the reliability requirements andperformance requirements.

[0060] If no matching record is found to be in compliance with theconditions where the above-mentioned two sets of requirements are ANDed,only the reliability requirements are used as the key to search thestorage destination volume versus storage requirement mapping table 510(step 704).

[0061] Only the performance requirements are used as the key to searchthe storage destination volume versus storage requirement mapping table510 (step 705). The storage destination records found in the searches insteps 704 and 705 are merged to generate a single search result (step706).

[0062] The search result obtained in step 706 is examined to check for amatching record. The program flow proceeds to step 709 if any matchingrecord is found or proceeds to step 708 if no matching record is found(step 707). If no storage destination volume is found to be compliantwith demanded storage requirements when steps 704 through 707 areperformed, the program flow searches for a storage destination volumethat satisfies either the reliability requirements or performancerequirements. Using the search result obtained in step 706 as a storagedestination candidate, the program flow proceeds to step 711 (step 709).Since no storage destination volume is found to be compliant with thereliability requirements or performance requirements, the program flowregards all storage destination volumes as storage destinationcandidates and proceeds to step 711 (step 708).

[0063] After checking whether one or more than one storage destinationvolume candidate is designated in the preceding step, the program flowproceeds to step 713 if only one candidate is designated or proceeds tostep 712 if two or more candidates are designated (step 711). Sincethere are a plurality of storage destination candidates, the programflow references the storage destination volume usage priority definitiontable 520, and performs calculations on the plurality of storagedestination candidates to select a storage destination volume having thehighest priority (step 712).

[0064] The selected storage destination volume is recorded as thestorage destination volume information 242 and then passed to thestorage step 304 (step 713). When a plurality of storage destinationvolumes satisfy the reliability requirements and storage requirements,steps 711 through 713 are followed as described above to performcalculations on such plurality of storage destination volumes to selectone specific storage destination volume in accordance with the prioritydefinition formulated in the storage destination volume usage prioritydefinition table 520.

[0065] An embodiment of the storage requirement calculation rule setupengine 102 and storage destination volume calculation rule setup engine103 will now be described.

[0066] The storage requirement calculation rule setup engine 102 sets upthe storage destination requirement calculation rule 181. FIG. 8 is aflowchart that illustrates an embodiment of the process performed by thestorage requirement calculation rule setup engine 102. The processconsists of two steps.

[0067] First, the user is prompted to manually enter the reliabilityrequirements and performance requirements for the file that a specificbusiness application stores (step 801). Next, the reliabilityrequirements and performance requirements entered in the preceding stepare stored in the storage requirement mapping table 410 (step 802). Asdescribed above, this embodiment assumes that the user manually sets upthe storage destination requirement calculation rule 181.

[0068] Alternatively, a business application developer may distribute asetup file to users to present the reliability requirements andperformance requirements for the files to be stored by a specificapplication. In this case, the setup file can be entered into thestorage requirement calculation rule setup engine 102 so that thestorage requirement calculation rule setup engine 102 interprets thesetup file to set up the storage destination requirement calculationrule 181.

[0069] The storage destination volume calculation rule setup engine 103sets up the storage destination volume calculation rule 182.

[0070] In the embodiment, the storage destination volume calculationrule setup engine 103 is characterized in that it dynamically calculatesthe storage destination volume calculation rule 182 in accordance withthe manufacturer information and volume type information, which can beobtained by issuing an inquiry command to a storage destination volume.

[0071]FIG. 9 illustrates the process that is performed by the storagedestination volume calculation rule setup engine 103. The process of thestorage destination volume calculation rule setup engine 103 will now bedescribed in detail with reference to FIGS. 9 and 5.

[0072] The user enters the reliability characteristics and performancecharacteristics in accordance with the volume manufacturer and type(step 901). The user has to enter the reliability characteristics andperformance characteristics for each volume type. Thevolume-type-specific reliability characteristics and performancecharacteristics entered in the preceding step are then stored in thevolume type versus characteristics mapping table 530 (step 902). Theprogram flow now clears all the records in the storage destinationvolume versus characteristics mapping table 510 and storage destinationvolume usage priority definition table 520 (step 903).

[0073] Next, a type inquiry command is issued to all the connectedstorage destination volumes 171 to acquire the information about theirmanufacturers and types. The type inquiry command can actually beimplemented by using SCSI's inquiry command or the like (step 904). Theinformation about a volume manufacturer and type, which is acquired inthe preceding step, is then used as the key to search the volume typeversus characteristics mapping table 530 (step 905).

[0074] The program flow proceeds to step 907 if a matching record isfound in the search conducted in the preceding step; however, if nomatching record is found, the program flow proceeds to step 910 (step906). In the former case, the reliability characteristics andperformance characteristics are acquired from the search result (step907). In the latter case, the default reliability characteristics andperformance characteristics in the volume type versus characteristicsmapping table 530 are acquired (step 910).

[0075] The information about the reliability and performancecharacteristics and the associated storage destination volume is addedto the storage destination volume versus characteristics mapping table510 as a record (step 908). The record of the same destination volume asfor the storage destination volume versus characteristics mapping table510 is added to the storage destination volume usage priority definitiontable 520 so as to assign usage priority levels 522 to the definitionsin the volume type versus characteristics mapping table 530 in ascendingorder of capacity unit price 535 (step 909).

[0076] The above steps are performed to ensure that a storagedestination volume having the lowest capacity unit price is used priorto the others when they satisfy the same storage requirements.

[0077] Since the storage destination volume calculation rule setupengine 103 uses the volume type information to automatically calculatethe reliability characteristics and performance characteristics of eachvolume as described above, the user need not take the trouble ofdefining the storage destination volume characteristics separately.

[0078] The present invention is not limited to the above embodiment, butextends to various modifications. In the above embodiment, for example,the storage destination requirement calculation rule 181 shown in FIG. 4and the storage destination volume calculation rule 182 shown in FIG. 5calculate the reliability requirements and performance requirements oncondition that both of these requirements be met. However, these rulesmay alternatively perform calculations on condition that either thereliability requirements or performance requirements be met. Somebusiness applications do not always require that the reliabilityrequirements and performance requirements be both met. For such businessapplications, the storage requirements can be defined with relativesimplicity.

[0079] The system of the embodiment makes it possible to achieve datastorage destination optimization on an individual file basis because itcalculates the storage requirements and selects a storage destinationvolume for each file. Further, it automatically selects the storagedestination volume in the storage requirement calculation step andstorage destination volume selection step, thereby saving theadministrator the bother of performing a complicated setup procedurewhile considering individual volumes and their mounting destinations. Asa result, the administrator of a storage system can accomplish datastorage destination optimization on an individual file basis withouthaving to perform a complicated setup procedure.

What is claimed is:
 1. A method for exercising file storage destinationvolume control in a file system in which data are selectively stored ona plurality of volumes in compliance with a file storage request from abusiness application, said method comprising: a storage requirementcalculation step for calculating reliability requirements or performancerequirements which are the storage requirements for a specific file forrequested storage; a storage destination volume selection step forselecting an actual file storage destination volume in accordance withthe calculated storage requirements and the reliability characteristicsor performance characteristics of each volume; and a file storage stepfor storing the file on the selected storage destination volume.
 2. Themethod according to claim 1, wherein said storage requirementcalculation step calculates the storage requirements by searching forpredefined business-application-type-specific storage requirements whileusing the type of a business application that has issued a storagerequest.
 3. The method according to claim 1, wherein said storagerequirement calculation step calculates the storage requirements bysearching for predefined user-specific storage requirements while usingthe identification information about a user who has issued a storagerequest.
 4. The method according to claim 1, wherein said storagerequirement calculation step uses the storage requirements directlyspecified by a business application as the calculation result.
 5. Themethod according to claim 1, wherein said storage destination volumeselection step selects a storage destination volume by referring to thestatically predefined reliability characteristics and performancecharacteristics of each volume and the storage requirements for the filerequested for storage.
 6. The method according to claim 1, wherein saidstorage destination volume selection step selects, when a plurality ofstorage destination volumes are chosen, a volume having the highestpriority by referencing a predefined priority level assigned to eachvolume.
 7. The method according to claim 1, wherein said storagedestination volume selection step inquires of each volume the volumetype information, uses the volume type information derived from theinquiry as the key to search for the predefined information about therelationship between the volume type information and the reliabilitycharacteristics and performance characteristics of each volume,calculates the reliability characteristics and performancecharacteristics of each volume, and calculates, upon a file storagerequest, a storage destination volume by referring to said calculatedreliability characteristics and performance characteristics of eachvolume and the storage requirements for the file requested for storage.8. A file server system for storing file data upon request from clientshaving a plurality of business applications, said system comprising: astorage device provided with a plurality of volumes for storing datawhich may be requested by clients; a main storage device for storing anOS for operating the system and retaining a storage destinationselection engine for making a storage destination volume selection foreach file in compliance with a storage request from a businessapplication running on a client, a storage requirement calculation rulesetup engine for setting up a storage destination requirementcalculation rule, and a storage destination volume selection rule setupengine for setting up a storage destination volume selection rule; and aCPU for executing, under the OS, the storage destination selectionengine, the storage requirement calculation rule setup engine, and thestorage destination volume selection rule setup engine, calculatingstorage requirements for each file, and selecting a file data storagedestination volume.
 9. The file server system according to claim 8,wherein said storage device includes a management information storagevolume for storing the management information about data storage,wherein said management information storage volume stores a storagerequirement calculation table which defines a relationship betweenbusiness applications and reliability requirements or performancerequirements, and a storage destination volume selection table whichdefines a relationship between storage destination volumes andreliability requirements or performance requirements, and wherein saidstorage device references the storage requirement calculation table whenexecuting the storage requirement calculation rule setup engine orreferences the storage destination volume selection table when executingthe storage destination volume selection rule setup engine.
 10. The fileserver system according to claim 8, wherein said storage device stores aprogram which exercises, upon a storage request from a businessapplication running on a client, a storage destination selection enginefunction of selecting a storage destination volume for each file, astorage requirement calculation rule setup engine function of setting upa storage destination requirement calculation rule, and a storagedestination volume selection rule setup engine function of setting up astorage destination volume selection rule, and loads the program intothe main storage device when the system starts up.
 11. The file serversystem according to claim 8, wherein said storage destination selectionengine comprises: a file reception module for receiving a file requestedfor storage in compliance with a storage request from a businessapplication; a storage requirement calculation module for referencing astorage requirement calculation rule to calculate the reliabilityrequirements and performance requirements for the file as storagerequirement information; a storage destination volume calculation modulefor referencing said storage requirement information and a storagedestination volume calculation rule to calculate storage destinationvolume information for storage destination volume definition; and astorage module for storing the file requested for storage on a storagedestination volume specified by said calculated storage destinationvolume information.
 12. The file server system according to claim 8,wherein said storage device includes a management information storagevolume for storing the management information about data storage, andwherein said management information storage volume includes a storagerequirement calculation table which registers the information about themean time between failure or average operating time as reliabilityrequirement information and the information about access speed asperformance requirement information in relation to the types of businessapplications that may issue a storage request.
 13. The file serversystem according to claim 8, wherein file data storage destinationvolumes are physical volumes, wherein registration means is provided forregistering reliability requirements or performance requirements todetermine the characteristics of the physical volumes, and wherein thestorage destination selection engine references the registration meansin compliance with a storage request from a business application todetermine the reliability requirements or performance requirements. 14.A method for exercising data storage control to store file data on aplurality of volumes, the method comprising the steps of: receiving afile data storage request from a business application; referencing thereliability requirements or performance requirements for the storage ofa file requested for storage to determine the storage requirements forthe file; selecting a file storage destination volume in accordance withthe determined storage requirements and the reliability characteristicsor performance characteristics of each volume; and storing the file dataon the selected storage destination volume.
 15. The method according toclaim 14, wherein the information indicating the mean time betweenfailure or average operating time is used as the information aboutreliability requirements while the information indicating the accessspeed is used as the information about performance requirements.
 16. Themethod according to claim 14, wherein the step of determining thestorage requirements for the file is such that a storage requirementcalculation module references a storage requirement calculation rulestored in a storage device to calculate the reliability requirements andperformance requirements for the file as storage requirementinformation.
 17. The method according to claim 14, wherein the step ofselecting the storage destination volume is such that a storagedestination volume calculation module references said storagerequirement information and a storage destination volume calculationrule to calculate storage destination volume information for storagedestination volume definition.
 18. The method according to claim 14,wherein the step of determining the storage requirements is such thatstorage requirement information is acquired by referencing a storagerequirement calculation table which registers the information about themean time between failure or average operating time as reliabilityrequirements and the information about access speed as performancerequirements in relation to the types of business applications that mayissue a storage request.
 19. A program which is executed on a computerto implement a function of exercising file storage destination volumecontrol in a file system for storing data on a plurality of volumes, theprogram comprising: a storage requirement calculation function ofcalculating reliability requirements or performance requirements as thestorage requirements for file storage in compliance with a file storagerequest from a business application; a storage destination volumeselection function of selecting an actual file storage destinationvolume in accordance with the calculated storage requirements and thereliability characteristics or performance characteristics of eachvolume; and a file storage function of storing the requested file dataon the selected storage destination volume.
 20. The program according toclaim 19, wherein said storage requirement calculation function acquiresstorage requirements by referencing a storage requirement calculationtable which registers the information about the mean time betweenfailure or average operating time as reliability requirements and theinformation about access speed as performance requirements in relationto the types of business applications that may issue a storage request.